Ukip leader Nigel Farage said there is “something quite unpleasant going on” in Scotland after his Ukip team was sprayed by a protester with a fizzy drink.

He and fellow-Ukip members were walking into a pub in Aberdeen after speaking to protesters when they were doused in cola.

The confrontation came a month after he was forced to take refuge in a pub in Glasgow from a group of baying protesters, before being escorted to safety by police.

In Aberdeen police detained a man after the fizzy drink was sprayed over members of the Ukip team most of it landing on David Coburn, chairman of Ukip London.

The drink-throwing followed a day of chaos for the Ukip campaigners who had to change a press conference venue when a hotel refused, they said, to honour a booking and had an invitation to tea with Aberdeen Council deputy leader Marie Boulton at the city’s Town House cancelled at the last minute.

Mr Farage said: “I was going to go for tea, which is a very civilised gesture and very much in line with the hundreds of emails I've had since Edinburgh saying: 'Please don't judge Scotland on the behaviour of a few students'. Clearly the invitation was issued but some pressure has been brought to bear, from whom I don't know.

”There is this narrative, and we saw it in Edinburgh a month ago, and I also saw it on Question Time last week … saying that Ukip's voice shouldn't be heard here. So every attempt is being made to stop us from speaking.

“I've never come across anything like it in all of my life anywhere in Britain, Europe or the world for that matter. There is something quite unpleasant going on.”

He was in Scotland to campaign on behalf of the Ukip candidate in the Aberdeen Donside Scottish Parliament by-election taking place on Thursday. The seat was made vacant by the death of SNP MSP Brian Adam.

Ukip blamed the two cancellations on threats. ”Police advised against the meeting at the townhouse. That of course indicates a problem with democracy in Scotland,” said Lord Christopher Monckton, the Ukip president in Scotland.

“Only one view - the party line - is permitted and anyone who wishes to go in another direction is threatened in the street, menaced, attacked and now we have a meeting cancelled because people wish to stop it by violence.”

He said of the cancellation of the booking Ukip believed it had at the Marriott Hotel: “We had agreed a very competitive price and we were getting two rooms to dine in and hold a press conference.

“However, when I then tried to telephone to ensure everything was confirmed my calls were not returned, and when I eventually managed to get through I was told another booking had offered more money.

”What we think happened was group calling themselves the Aberdeen Anti-Fascist Alliance had threatened to cause a disturbance at the press conference. We think the Marriott behaved in a manner that fell short of what we would regard as professional.“